node_exporter enable memory buddyinfo monitoring

[wangkedba]

Feature Request

node_export can collect exposes statistics of memory fragments as reported by /proc/buddyinfo. But this feature is disable by default. It's usefull to locate memory problems,so we hope to open it by default , both tiup and ansible deploy.

Add parameters '--collector.buddyinfo' to the node_exporter startup script.
Is your feature request related to a problem? Please describe:

Locate memory problems
Describe the feature you'd like:

Describe alternatives you've considered:

Teachability, Documentation, Adoption, Migration Strategy:

[9547]

Good idea, I'll try to implement it those days.